Possible Kidney Complications after Application of Cell Technologies for the Repair of the Resected Liver.

The state of rat kidneys after injection of bone marrow multipotent stromal cells (MSC) labeled with Vybrant CM-Dil into intact or resected liver was studied by fluorescence microscopy. The main structural changes in the kidneys after MSC injection into intact and partially resected liver manifested as granular dystrophy and necrobiotic/necrotic changes in single epithelial cells of the distal tubules and collecting ducts, thrombosis of some vessels, progression of an ascending urinary tract infection (detection of dust-like fluorescent objects), which can be due to the immunomodulating or even immunosuppressive influence of MSC and their detritus. MSC injected into the intact or resected liver, as well as the products of their degradation were not detected in the kidneys at all terms of observation. After injection of MSC into partially resected liver, manifestations of bacterial contamination of the renal medulla appeared later. The injection of MSC into the liver can be complicated by thrombosis of the renal vessels, which should be taken into account when using this administration route in the cell therapy.

Dissemination of Multipotent Stromal Cells in the Organism after Their Injection into Intact and Resected Liver in the Experiment.

The possibility of dissemination of bone marrow multipotent stromal cells stained with Vybrant CM-Dil after injection into an intact and resected liver was studied using luminescence microscopy. Labeled cells were found in the kidneys, spleen, lungs, axillary, mesenteric, and inguinal lymph nodes. We observed dissemination of multipotent stromal cells and their detritus throughout the body that occurred only after filtration in the lungs, where most cells underwent destruction. Perivascularly located macrophages in various organs can phagocytize multipotent stromal cells and their detritus from blood vessels. The content of objects labeled with Vybrant CM-Dil in distant organs was significantly lower after multipotent stromal cell injection into the resected liver, which was associated with the deposition of cells in the damaged area of the organ and their partial entry into the abdominal cavity.

Preservation of Mesenchymal Stem Cell-Derived Extracellular Vesicles after Abdominal Delivery in the Experiment.

Light luminescent microscopy was used to study the distribution of extracellular microvesicles with PKH26-stained membranes secreted by placenta-derived mesenchymal stromal cells in the uterine tissues at different terms after injections to intact rats and after abdominal delivery (a model of cesarian section). Microvesicles migrated through the uterine tissues and were detected for at least 8 days after injection. In some cases, microvesicles were more numerous in the uterus after cesarian section modeling, which can be related to blockade of microcirculation and lymph flow due to inflammation accompanying surgical intervention. The content of microvesicles in the uterine tissues gradually declined due to macrophage phagocytosis and, probably, due to their migration into the vascular bed. Despite their size, properly stained extracellular microvesicles can be detected by light microscopy in tissues after injections.

[Liver regeneration after resection in clinical and experimental conditions]. / Nekotorye aspekty regeneratsii pecheni posle rezektsii v klinike i eksperimente.

The researches devoted to postoperative liver regeneration and influence in this process were analyzed. Liver injury is followed by hypertrophy of residual liver parenchyma. The use of various cytokines is perspective for activation, acceleration and inhibition of liver recovery. Cellular technologies in the treatment of liver diseases can affect its repair. Moreover, these methods could make unnecessary resection and transplantation of liver in certain cases. It is generally accepted that the main effect of multipotent stromal cells (MSC) in liver failure is associated with their differentiation to the cellular elements of this organ. At the same time, recent reports revealed that MSC injection to the liver is followed by their quick death, dissemination to other organs and tissues or even elimination from the organism. Regeneration of non-parenchymal structures (vascular network and bile ducts) should be considered in addition to functional recovery of liver parenchyma after resection. Clarification of indications and contraindications for MSC therapy, as well as prevention of possible complications associated with cellular technologies are required.

[Age-related changes of the female urethra.]

The minimum and maximum indicators of the length, width, area or volume of organs and structures in the lower urinary tract can normally vary up to 2-3 times. With age, at healthy women the absolute and relative length of the urethra, the urethrovesical angle, and the inclination of the urethra do not change. Both smooth and striated muscle tissues, which are part of various departments of the female urethra, undergo atrophy during the aging process. Smooth muscle tissue is less variable with age, but striated muscle symplasts are sometimes completely absent in urethral biopsies from elderly patients. With age, the vascularization and density of the innervation decrease in the urethral structures, but the content of connective tissue in the external urethral sphincter increases. Urinary tract mobility at young women is more pronounced than at older women. The apparent insufficiency of modern investigations about age-related changes in the lower urinary tract indicates the relevance and need to continue studying of the organ and tissue transformation in the urinary system during aging, this may be important for determining the etiology and pathogenesis of some pathological conditions, such as stress urinary incontinence, as well as for differential diagnosis between age norm and pathology.

Injection of Multipotent Mesenchymal Stromal Cells as a Cause of Hemorrhages in the Regional Lymph Nodes: Experimental Study.

Hemorrhagic changes after subcutaneous injection of autologous bone marrow multipotent mesenchymal cells with transfected GFP gene and additionally stained cell membranes to WAG rats in the projection of ligated femoral vein were studied by fluorescent microscopy. Hemorrhages in tissues with experimental acute local venous occlusion were caused by a combination of venous hypertension with inflammation around the foreign body - the ligature used for ligation of the vein. Fibrin found in tissues together with erythrocytes in the hemorrhages could stimulate the formation of granulations and new vessels instead of damaged or thrombosed ones. Multipotent mesenchymal stromal cells and their detritus getting into the regional lymph nodes initiated immune reactions morphologically confirmed by stubborn hypertrophy and hyperplasia of the lymphoid nodules, hemorrhages, and manifest diapedesis of erythrocytes to the organ parenchyma and sinus system.

Some Peculiarities of Local Distribution of Multipotent Mesenchymal Stromal Cells after Their Injection into Intact Muscle Tissue in Experiment.

Changes in the muscular tissue after subcutaneous injection of autologous bone marrow multipotent mesenchymal stromal cells transfected with GFP gene and additionally stained with cell membrane dye Vybrant CM-Dil in the projection of ligated femoral vein were studied by light microscopy with luminescence. Stromal cells injected through the skin can appear not only in the damaged tissue where acceleration of regeneration processes is required, but also in intact structures located in superficial or deeper layers. In intact muscular tissue, stromal cells spreading in the perivascular tissue initiate inflammation and migration of macrophages, activate and even trigger sclerotic processes due to differentiation into connective tissue cells (fibroblasts) and stimulation of proliferation and collagen synthesis by host fibroblasts. Injected multipotent mesenchymal stromal cells are gradually phagocytized by macrophages.

Results of Experimental Ligation of the Main Vein with the Use of Cell Technologies.

Autologous multipotent mesenchymal stromal cells (MMSC) of bone marrow origin with transfected GFP gene and additionally stained cell membranes were injected to rats through the skin in the projection of ligated femoral vein. The results were evaluated by fluorescent microscopy. No signs of MMSC incorporation into the wall of ligated vessel or reorganized collaterals were detected. Angiogenesis processes involving MMSC were detected in experimental rats within just 4 days and progressed until week 2 postinjection, mainly in granulations at the site of surgical intervention and the cicatrix forming there. Injected MMSC completely formed all tunics of the new vessels and incorporated in the vessels forming from the recipient cells. MMSC and the objects created from them were gradually eliminated with participation of macrophages and replaced by structures formed from the recipient cells.

Correction to: Possibility of Aggravation of Tissue Sclerosis after Injection of Multipotent Mesenchymal Stromal Cells Near the Forming Cicatrix in the Experiment.

The author name G. A. Chastikina should read G. A. Chastikin.

Possibility of Aggravation of Tissue Sclerosis after Injection of Multipotent Mesenchymal Stromal Cells Near the Forming Cicatrix in the Experiment.

The peculiarities of tissue sclerosis after injection of autologous bone marrow multipotent mesenchymal stromal cells transfected with GFP gene and stained with Vybrant CM-Dil cell membrane dye were studied by light microscopy with luminescence. The surgical intervention consisting in ligation of the great vein was followed by tissue sclerotic transformation caused by direct damage and chronic inflammation caused by the presence of slowly resorbed ligature. Injection of stromal cells after this intervention led to formation of more extensive scar. This can attest to the possibility of stromal cells differentiation into connective tissue cells, fibroblasts, and stimulation of proliferation and collagen synthesis by host fibroblasts. A decrease in the volume of dense fibrous connective tissue due to scar reorganization at latter terms cannot not excluded.

[THE PECULIARITIES OF UTERINE STRUCTURE AFTER DELIVERY IN RATS WITH THE MYOMETRIAL SCAR].

The uterine tissues of female rats (n=30) with a scarred myometrium were examined by methods of light microscopy after the delivery. 1.5-2 months after the delivery no significant differences in the parameters of blood and lymph flow in the deep layers of the endometrium, myometrium and the myometrial scar tissue were found between the intact rats, nulliparous rats with a scarred uterus, rats that gave birth after laparotomy only and those that gave birth under the conditions of myometrial scar. In the course of pregnancy and labor activity, the damage of the tissues was observed not in the uterine scar proper, but at its borders with the myometrium. This is supported by the old hemorrhages and lymphostasis phenomena, greater number of lymphocytes, neutrophils, monocytes, macrophages and erythrocytes. In determining the indications and contraindications to vaginal childbirth in women with scarred uterus it is necessary to examine not only the scar proper, but also its border with the myometrium. The myometrial scar by itself, is not an absolute contraindication to vaginal delivery, the natural delivery is feasible in the absence of cavities with liquid and hemorrhages in the tissues of the uterine scar and at its border with myometrium.

[Peculiarities of tissue reactions to implantation of non-degradable surgical materials].

The method of light microscopy was used to study the reactions of the surrounding tissues to the implantation of non-degradable surgical materials (prolene 3/0 thread made from polypropelene, the composite grid made from polypropelene or polyester with polylactic acid) in the subcutaneous adipose tissue of rats 1, 2, 6 and 12 months after grafting. No less than 6 rats were examined in every time point. It was shown that the tissue reactions to implantation of different non-degradable surgical materials follows the general pattern, characteristic of wound process and foreign body reaction. By the first month of observation in both groups of animals the stage of traumatic perifocal inflammation was replaced by the proliferative phase with the formation of new blood vessel and connective tissue. The tendency to reduction of the activity of productive inflammation was observed from the 1st to the 12th month together with the increased fibrous scar transformation of the granulation tissue.

Local tissue reaction to implantation of biodegradable suture materials.

Morphological changes in tissues adjacent to the implant were studied 1, 2, 6, and 12 months after implantation of biodegradable suture materials (catgut thread, DemeTECH polyfilament thread, and Surgilactin monofilament thread) into subcutaneous fat of rats. Tissue reaction to implantation of different suture materials developed as usual in response to a wound process and to a foreign body. By the end of month 1. the stage of traumatic perifocal inflammation was replaced in all groups by the proliferative phase with formation of new vessels and connective tissue. A trend to reduction of the productive inflammation activity from month 1 to month 12 was noted. Complete degeneration of the material after 12 months with complete recovery of the histoarchitecture of the adjacent tissues (restitution) was detected only after implantation of DemeTECH polyfilament thread.

Reaction of rat tissues to implantation of lactic acid-based biodegradable polymer.

Polylactide degradation processes after its implantation into the subcutaneous fat of rats were studied by microscopy. After implantation polylactide was encapsulated in connective tissue. If a fragment of polylactide had sharp edges, injuring the tissue, a thick capsule formed with pronounced inflammatory infiltration and sclerosis of adjacent tissues. If the implant had no sharp edges, the capsule was thin and the level of inflammation the minimum. Foreign body giant cells were found in the capsule and near it in all cases. The activity of the inflammatory process gradually reduced over 6 months. The intensity of inflammation sharply increased by the 12th month after implantation, when activity of phagocyte enzyme and deformation by the capsule led to fragmentation or liquefaction of polylactide.

[Tissue responses to silicone materials in the body].

Light microscopy was used to study connective tissue capsules formed around different silicone breast implants. It has been found that due to the activity of microfibroblasts to minimize the volume of foreign bodies, the capsule gradually shrinks; its inner surface deforms and develops an undulating appearance with a multitude of outgrowths or protrusions inside. With the passage of time, silicone migrates to the capsule tissue and outside where it is absorbed by phagocytes. The inerter to a living organism the implant material is, the less it will stimulate a macrophage response. The task of designing new implants is to search for maximally bioinert materials that are strong enough to be compressed by the capsule and be fragmented and, moreover, elastically similar to normal breast tissue.

[Tissue reactions during the degradation of polylactide implants in the body].

Tissue reactions, accompanying the degradation processes of polylactide (PLA) implants after their placement into the subcutaneous tissue, were studied by the methods of light microscopy in 6 month-old Wag rats (n=24) weighing 180-200 g. It was found that PLA implants became encapsulated by connective tissue. If the implant or its fragment had sharp margins that damaged the tissues, a thick capsule was formed with a distinct inflammatory infiltration and the sclerosis of the surrounding tissues. If the implant had no sharp margins, the capsule was thin, and the activity of inflammation was minimal. In all cases, the giant cells of foreign body type were present in the capsule and next to it. Gradually, during 6 months, the activity of inflammatory process subsided. Inflammation sharply increased 12 months after the implantation, when, as a result of effect of enzymes released by phagocytes and deformation by a capsule, PLA implants were either fragmented or is liquified. PLA-based materials are not totally biodegradable, and may persist in the body for a long time.

[Morphological tissue changes after the implantation of a biodegradable material on collagen basis].

The objective of this study was to examine the peculiarities of tissue reactions during the degradation of "Collost" bioplastic material on the collagen basis with completely preserved fibrous structure, after its implantation into the bone tissue defect. The defect in bone tissue sized 1-2 mm x 3-5 mm was created in tibial condyle. The study was performed on 24 Wistar rats using light microscopic methods. The tissue reactions were studied at different time intervals (1, 2, 6 and 12 months) after the implantation of collagenic material. It was found that after the implantation, the material became impregnated with blood, and due to fibrin, densely adhered to the damaged tissues. Further, the cells were found to migrate along the blood clot into its depth from the surrounding tissues. These were primarily the fibroblasts which were located in a network of fibers and started to absorb collagen from a surrounding material and to synthesize new collagen. Gradually, the collagenic material became similar to a cell-containing network. The volume of the newly synthesized collagen increased, and after some time all the foreign material was absorbed by fibroblasts and replaced with connective tissue. After 1 year, a large "Collost" fragment was completely degraded and replaced by loose connective tissue. The implantation of a collagenic material did not stimulate the formation of a delimiting connective tissue capsule

[Peculiarities of tissue reactions during resorption of biodegradable suture materials].

The reaction of the surrounding tissues to the implantation of biodegradable suture materials (plain catgut threads, DemeTECH polyglactin 910, Surgilactin--polyglactin 910) into the subcutaneous adipose tissue of rats, was studied using light microscopy 1, 2, 6 and 12 months after grafting. It was shown that the tissue reactions to implantation of different biodegradable suture materials followed the general pattern characteristic of wound healing and foreign body reaction. By the first month of observation, in all the animal groups, the stage of traumatic perifocal inflammation was replaced by a proliferative phase with the new growth of the blood vessels and connective tissue. In all the animal groups, there was a trend to reduction of productive inflammation activity from the 1st month till the 12th month. By the 12th month the total degeneration of the material with full recovery of structure of surrounding tissues (restitution) was recorded only after the implantation of polyglactin 910 (DemeTECH).

Morphology of pararectal lymph nodes in rectal cancer after neoadjuvant therapy.

Remodeling and cytograms of pararectal lymph nodes were studied in patients with rectal cancer after neoadjuvant therapy by different protocols. Radiotherapy and its combination with chemotherapy lead to an increase in the volume of connective tissue components and significant reduction of the volume density of lymphoid follicles without germinative centers. The counts of dividing cells, immunoblasts, and plasmoblasts in various compartments of the pararectal lymph nodes changed more significantly after radiotherapy, while changes in the count of monocytes and neutrophils were more pronounced after cytostatic therapy combined with exposure to ionizing radiation. These differences can be explained by the systemic toxic effect of chemotherapeutic drugs and primarily local cytotoxic effects of radiotherapy manifesting largely at the site of exposure.

[Characteristics of changes in the axillary lymph nodes without metastases after chemotherapy in patients with mammary gland cancer].

Light microscopy of the axillary lymph nodes in 74 relatively healthy women and in 186 patients with mammary gland cancer revealed that the lymph nodes of 10.8% of the patients contained no substantia medullaris: the tractus pulposus and cerebral sinuses were replaced by various types of the connective tissue. Similar signs in the relatively healthy women were much rarer (5.4%). The frequency of the sclerotic transformation was shown to be not dependent on the neoadjuvant chemotherapy of the mammary gland cancer but increased with aging of the subjects. After the use of polychemotherapy followed by long-term traumatic surginal interventions, tissue detritus and blood formed elements were detectable in the sinus system of the regional lymph nodes.